[U-Boot] About convert to LIVE DT

[Simon Glass]

Hi Kever,

On 4 February 2018 at 18:00, Kever Yang <kever.yang at rock-chips.com> wrote:
>
>
> On 02/04/2018 09:40 PM, Simon Glass wrote:
>> Hi Kever,
>>
>> On 4 February 2018 at 00:44, Kever Yang <kever.yang at rock-chips.com> wrote:
>>> Hi Simon, Philipp,
>>>
>>>     When I try to convert to live dt, I fount there are many APIs work
>>> in fdt are missing in live dt,
>>>
>>> do you have any suggestion to add these APIs in live dt quickly? I need:
>>>
>>> fdtdec_get_addr_size_auto_noparent
>> dev_read_addr_size() - not having a parent doesn't happen with livetree
>>
>>> fdt_alloc_phandle
>> We don't support changing the live tree yet.
>>
>>> fdt_device_is_available
>> dev_read_enabled()
>>
>>> fdt_for_each_subnode
>> dev_for_each_subnode()
>>
>>> fdt_getprop
>> dev_read_prop()
>>
>>> fdt_getprop_u32_default_node
>> This is an odd function. Can you first check that the property exists,
>> and then use a dev_read_...() function to read it?
>>
>>> fdt_get_named_resource
>> dev_read_resource_byname()
>>
>>> fdt_get_name
>> dev_read_name() - although I see that the comment is wrong
>>
>>> fdt_get_path
>> Not available but you can add it
>>
>>> fdt_get_phandle
>> Why do you need this?
>
> Most of the APIs are used in this file or other files in this folder,
> https://github.com/rockchip-linux/u-boot/blob/release/drivers/video/drm/rockchip_display.c
> It needs to handle quite complicated dts node for display system in
> rockchip drm display driver(not upstream yet):
> https://github.com/rockchip-linux/u-boot/blob/release/arch/arm/dts/rk3128.dtsi#L421
> https://github.com/rockchip-linux/u-boot/blob/release/arch/arm/dts/rk3126-bnd-d708.dts#L114

One difference I see with Linux is that U-Boot creates devices for all
nodes automatically, provided that they have a compatible string and
matching driver. This should simplify things in U-Boot.

The supernode-at-depth function looks like it just takes the parent of
the parent when an argument of -2 is used.

The existing rockchip driver in U-Boot handles a similar binding,
doesn't it? It has phandles and multiple nodes and subnodes.

>
> Thanks,
> - Kever
>>
>>> fdt_node_depth
>>> fdt_node_offset_by_phandle
>>> fdt_node_offset_by_phandle_node
>> uclass_get_device_by_phandle() or similar?
>>
>>> fdt_path_offset
>> ofnode_path() although it does not return a device. Best avoided.
>>
>>> fdt_set_phandle
>> You can't change the livtree at present.
>>
>>> fdt_stringlist_get
>> dev_read_string_index()
>>
>>> fdt_stringlist_search
>> dev_read_stringlist_search()
>>
>>> fdt_subnode_offset
>> Why do you want that?
>>
>>> fdt_supernode_atdepth_offset
>> This should be found by scanning, generally using separate drivers for
>> each DT node.
>>
>> If you like you could send a patch with the info above, to
>> doc/driver-model/livetree.txt to help others.

Regards,
Simon